As in the above cross-referenced application, the PSTN is defined presently as the aggregate world-wide of all equipment (both land-based and radio equipment) operating to interconnect telephones used by members of the public at large, but excluding equipment restricted to specific users (e.g. networks formed by PBX's, Centrexes, etc.) as well as public data networks such as the Internet. Although connections to the Internet are formed through the PSTN, for this application the Internet itself is viewed as external to the PSTN.
Today, the PSTN supports both voice telephone and facsimile (fax) type transmissions between its customers/users. Fax transmissions are conducted between special purpose fax machines, between computers using so-called "fax modems", and between special purpose fax machines and computers equipped with fax modems. However, present handling of fax transmissions is inadequate for many PSTN users.
For example, a user preparing for a voice conference with other users, and having a number of charts to present, can not simply broadcast facsimile copies of the charts to all prospective conference attendees, and transmitting such copies sequentially to prospective attendees requires that an operating fax machine or the equivalent be closely accessible to each prospective attendee, and also pre-supposes that all of the fax machines so deployed will operate satisfactorily (not fail) during the transmissions.
Also, there are times when it would be desirable to be able to concurrently transmit voice and graphic or text images through the PSTN--e.g. during conference calls between PSTN users having suitable viewing equipment--and present PSTN facilities do not allow for this to be accomplished in a manner that would be both cost effective to PSTN users and add minimal bandwidth stresses to the existing PSTN transmission infrastructure.
The present invention is directed to offering an effective solution to these problems within the PSTN which requires virtually no change to existing transmission infrastructures of the PSTN, and minimal software changes to intelligent peripheral entities presently contemplated for AIN facilities of the PSTN.